Electromagnetic wave scattering from a rough interface above a chiral medium: generalized telegraphists' equations

Using complete modal expansions for the electromagnetic fields above and below a rough interface between free space and chiral media and on imposing exact boundary conditions at the interface, Maxwell's equations are converted into generalized telegraphists' equations for the wave amplitudes of different species of waves (radiation far fields, lateral, and surface waves). The local basis functions, used in the complete modal expansions, are functions of the fluctuating surface height and medium parameters. The generalized telegraphists' equations are coupled first-order differential equations for the forward- and backward-traveling wave amplitudes. The coupling between the different species of waves is due to the fluctuations of the rough surface height and medium parameters. A Taylor series expansion of the surface element scattering matrix in terms of the chiral parameter is used to distinguish between depolarization due to surface roughness and the chiral properties of the medium. The analysis has applications in remote sensing and identification of biological and chemical materials through their optical activity.

Electromagnetic wave scattering from a rough interface above a chiral medium: generalized field transforms

In order to derive full-wave solutions for electromagnetic wave scattering from rough interfaces between achiral media (free space for instance) and chiral media that satisfy generalized constitutive relations, it is necessary to employ complete modal expansions for the electromagnetic fields above and below the interface. To this end, the familiar Fourier transforms of the fields are expressed as generalized field transforms consisting of the radiation term, the lateral waves, and the surface waves. Maxwell's equations are converted into generalized telegraphists' equations [in the companion paper (this issue), J. Opt. Soc. Am. A 30, 335 (2013)] upon the imposition of exact boundary conditions. These telegraphists' equations are coupled first-order differential equations for the forward- and backward-traveling wave amplitudes associated with all the different species of waves (radiation, lateral, and surface waves) excited at the surface of the chiral medium. The analysis presented here includes the completeness and orthogonal relations of the basis functions associated with the modal expansions. This work is used to distinguish between depolarization due to the chiral properties of the medium and depolarization due to surface irregularities. It has applications in remote sensing and identification of biological and chemical materials based on their optical activity.

Double-scatter cross sections for two-dimensional random rough surfaces that exhibit backscatter enhancement

Full-wave solutions are given for the single- and double-scatter radar cross sections for two-dimensional random rough surfaces. High-frequency approximations are used for the double-scatter cross sections in order to express them as numerically tractable four-dimensional integrals. The major contributions to the double-scatter cross sections are associated with the quasi-parallel and quasi-antiparallel double-scatter paths. They come from the neighborhoods of specular points. The enhancement of the backscatter cross sections, which is associated with the quasi-antiparallel double-scatter paths, is observed for both the like- and cross-polarized cross sections.

Reagents for the chemical development of latent fingerprints: scope and limitations of benzo[f]ninhydrin in comparison to ninhydrin

Benzo[f]ninhydrin was compared to ninhydrin for fingerprint development on paper. Overall, the performance of ninhydrin on exhibits was slightly better than that of benzo[f]ninhydrin. The significant advantages of the benzo[f]ninhydrin over ninhydrin were the much stronger fluorescence it gave after treatment with zinc salts and a slightly quicker reaction under ambient conditions. This fluorescence is, however, similar to that obtained with other reagents, such as DFO or ninhydrin analogs. These advantages apparently are not sufficient to justify regular usage of benzo[f]ninhydrin, especially when one considers its low solubility and high cost.

Computations of the Mueller matrix elements for scattering from layered structures with rough surfaces, with applications to optical detection

A full-wave method is used to evaluate the Mueller matrix elements for scattering from layered structures with random rough surfaces. These provide a database for applications in optical detection over a broad range of rough surface statistical parameters. They can be used to determine the optimal frequencies and incident angles that provide most reliable measurements for optical detection. The elements of the Mueller matrix that are most sensitive to medium parameters of the layered structures can also be identified. Contributions from individual terms of the full-wave solutions are shown to have distinct physical interpretations.

Scattering by layered structures with rough surfaces: comparison of polarimetric optical scatterometer measurements with theory

A laboratory model of a layered structure with a rough upper surface (a glass microscope slide cut with a diamond saw) is used to obtain optical polarimetric data. Scatterometer measurements were made of all the Mueller matrix elements associated with light scattered in arbitrary directions. (A preliminary measurement of scattering from a smooth opaque gold film on a silicon wafer was used to validate the calculation of the Mueller matrix elements.) These measurements are compared with corresponding analytical solutions based on the full-wave approach. Physical interpretations of the analytical solutions that account for scattering upon reflection and transmission across rough interfaces are given in a companion paper. The agreement between calculations and measurements suggests that the full wave, polarimetric solutions can provide a reliable database for electromagnetic detection of rough surfaces in remote-sensing applications.

Structural plasticity of optic synapses in the rat suprachiasmatic nucleus: adaptation to long-term influence of light and darkness

Synapses of optic afferents (optic synapses) in the suprachiasmatic nucleus of hooded rats were morphometrically evaluated after exposing the animals to 12 h, 14 days, 2 months, and 8 months of constant light (light rats) and darkness (dark rats). Compared with dark rats, optic synapses from light rats have larger boutons with larger mitochondria, more clear vesicles, fewer dense-core vesicles and front-line vesicles, smaller presynaptic dense projections, a smaller amount of postsynaptic density material, a smaller relative number of Gray-type I (asymmetric) junctions, a greater relative number of Gray-type II (symmetric) junctions, as well as more and larger mitochondria in the postsynaptic dendrites. Junctions of optic synapses are mostly straight, but the small number of positively curved contacts are more flattened in light rats than in dark rats. An age-related increase in the size of presynaptic dense projections was also observed. There are no changes in the sizes of clear and dense-core vesicles, in the size of synaptic junctions and their numerical density in area, and in the unspecific contact area between pre- and postsynaptic elements. The changes in optic boutons are characteristic for activated and relatively disused synapses with a slow, tonic firing rate. It appears that (1) the amount of postsynaptic density material is proportional to the strength of Gray-type I synapses, and that (2) some excitatory optic synapses become inhibitory after long-term activity, whereas some inhibitory synapses turn into excitatory contacts after long-term disuse.

Personal and domestic hygiene and its relationship to the incidence of diarrhoea in south Sumatera

The association of risk factors and diarrhoeal disease incidence among children less than 3 years of age in District Rambutan, South Sumatera, was investigated by a 20-week case-control study of 48 households with a high incidence of diarrhoeal diseases and 111 households with low incidence. Among sociodemographic characteristics, television ownership had a significant negative association with diarrhoeal disease incidence (odds ratio [OR] 3.22). The hygiene behaviour significantly associated with diarrhoeal diseases were: disposing of children's faeces in open places rather than in a latrine (OR > 10.47); bathing children in rivers rather than at wells (OR 2.88); children eating with their hands rather than with spoons (OR 5.6); household members defecating in open places rather than a latrine (OR 2.56); house without sewage system (OR 6.98). To control diarrhoeal disease in the study area, we suggest targeting three groups of behaviour for modification: those related to a) faeces disposal, b) sanitary drainage, and c) handwashing with soap and using spoons for eating.

Identification of contaminant coatings over rough surfaces using polarized infrared scattering

An optical technique to identify the presence of chemical coatings over rough surfaces is described. It is based on the selective use of elements of the 4 x 4 Mueller matrix. The full-wave theory of electromagnetic scattering is used to predict six independent Mueller elements from randomly rough uncoated (dry) and coated (wet) surface materials as functions of the media complex dielectric coefficients, backscattering angle, and midinfrared wavelengths of laser-beam excitations that are polarization modulated. The set of independent elements at beam wavelengths and backscattering angles [M(mn) (lambda(i), lambda(i))] most sensitive to i optically thick contaminant coatings are statistically obtained from the full-wave database, and detection-parameter sets [lambda(i), lambda(i)] are inputs to another algorithm designed to identify the contaminant coating (when present and interacted by the irradiating beams). These algorithms facilitate the operation of a multi-CO(2) laser-ellipsometer facility now under development at the U.S. Army Chemical Research, Development, and Engineering Center for the remote detection of chemical or biological surface contaminants.

An epidemiological study of mental health and socioeconomic conditions in Sumatera, Indonesia

A mental health survey was conducted in Palembang, Indonesia, to test the hypothesis that rapid socioeconomic and cultural change is detrimental to mental health. The 30-item General Health Questionnaire, translated into Bahasa Indonesia, was administered to a probability sample of 1670 adults (94.9% of the target sample). The Present State Examination was conducted on a weighted subsample of 100, using a 2-phase design. Overall morbidity rates were surprisingly similar to those in industrialized countries. A strong association was found between psychological symptoms and poverty. Persons belonging to communities that had progressed substantially in standards of living had fewer symptoms. The evidence points to a possibly beneficial effect of economic progress on mental health. Longitudinal data are needed to confirm this.

Backscatter cross sections for randomly oriented metallic flakes at optical frequencies: full wave approach

The backscatter cross sections for randomly oriented metallic flakes are derived using the full wave approach. The metallic flakes are characterized by their surface height spectral density function. Both specular point and Bragg scattering at optical frequencies are accounted for in a self-consistent manner. It is shown that the average normalized backscatter cross sections (per unit volume) for the randomly oriented metallic flakes are larger than that of metallic spheres.